ABIDJAN, Nov 28 (Reuters) - Central African Republic needs
up to four times more peacekeepers than are now deployed to
quell a worsening sectarian conflict and provide security for
aid workers, the European Union's top humanitarian official
said.

The country has descended into chaos since the Seleka
coalition of rebels, many of them from neighbouring Chad and
Sudan, ousted President Francois Bozize in March.

France is preparing to boost its force in its anarchic
former colony to at least 1,000 soldiers once a U.N. resolution
is passed next week to improve security until a 3,600-strong
African Union (AU) force is operational.

Paris, which already has around 400 troops based at the
airport in the capital Bangui, has already started beefing up
personnel and equipment in the country, diplomatic sources said.

Two sources also said France's ambassador to Central African
Republic was being replaced, replicating a change of its envoy
in Mali two months after French troops launched a mission there
earlier this year to oust al Qaeda-linked militants.

France's foreign ministry was not immediately available for
comment.

Around 2,500 regional peacekeepers deployed in the country
are to be brought into the AU force.

"Clearly what needs to be done is beefing up of peacekeeping
forces. Tripling or quadrupling what is there," EU aid chief
Kristalina Georgieva said, warning they face a twin risk of a
Somalia-like state collapse and potential genocide.

LOOMING TRAGEDY

"Unless there is an immediate, significant change in
security conditions, these two risks can deepen so much that we
have a tragedy on our hands. And we'll look back and say 'why
didn't we act sooner'," she said.

Some 460,000 people, a tenth of the population, have fled
the sectarian violence since the takeover by the mainly Muslim
Seleka rebels, whose numbers Georgieva said had grown from
around 5,000 fighters to some 20,000 today.

Fearing that tit-for-tat killings could escalate into
full-blown war between the Christian majority and Muslims, who
represent around 15 percent of the population, world powers are
scrambling into action.

U.N. Secretary-General Ban Ki-moon this month ordered his
officials to start preparing for the likely deployment of a U.N.
peacekeeping mission. But African leaders want to give the AU
force time to try to stabilise the situation.

"There has to be a commitment now - not in one month, not in
three months, now - to strengthen security," Georgieva told
Reuters late on Wednesday during a visit to Ivory Coast.

She said rapidly deteriorating security was already
hampering humanitarian assistance to the country of 4.6 million
people and aid agencies worried that their workers could soon
become targets of militia fighters.

Two local employees of the French humanitarian organisation
ACTED were robbed and murdered in the country in September.

The French-drafted U.N. resolution would give a six-month
mandate for French troops and the African-led International
Support Mission (MISCA) to restore order, protect civilians and
rebuild state authority.

"French troops will secure the main arteries and secondary
roads," said a French diplomatic source. "It's completely
feasible. This is neither al Qaeda in Mali nor al Shabaab in
Somalia. I wouldn't say the Seleka is a flock of sparrows, but
it should disband pretty quickly."
(Additional reporting by John Irish in Paris; Editing by Bate
Felix and Gareth Jones)